Ball-caster



No. 6|6,4|L Patented- Dec. 20, I898. E. L. DIMMITT.

BALL EASTER.

(Appiication filed Jan. 14. 1898.)

(No Model.)

FL? I E 321 W/TNESSES 7'0 I awn-i1, I'cmmtt 6% 5 ATTORNEY,

UNITED STATES PATENT OFFICE.

EDIVARD L. DIMMITT, OF KANSAS CITY, MISSOURI.

BALL-CASTER.

SPECIFICATION forming part of Letters Patent No. 616,411, dated December20, 1898.

Application filed January 14, 1898- Seria1N0.666,592. (N0 model.)

To (tZZ whom it may concern:

Be it known that I, EDWARD L. DIMMITT, a citizen of the United States,residing in Kansas City, in the county of Jackson and State of Missouri,have invented certain new and useful Improvements in UniversalBall-Bearing Casters, of which the following is aspeciiication,reference being had therein to the accompanying drawings.

My invention relates to improvements in ball-bearing casters.

The object of my invention is to provide caster that may be used on thelegs of chairs, tables, and other furniture.

My invention is also applicable to trunks, chests, skates, and, in fact,most any article requiring a rolling support.

My invention provides a caster that is cheap in construction, easilyapplied to the place of use, and in which the main supporting roller orball is capable of universal rotatory movement with a minimum offriction.

My invention provides,further,certain new and useful features ofconstruction hereinafter fully described and claimed.

In the acccmpanyin g drawings, which illustrate my invention, Figure Irepresents a side elevational view. Fig. II represents a verticalsectional view of a caster secured to the lower end of a chair-leg. Fig.III represents aplan view. Fig. IV represents a horizontal sectionalview taken on the dotted line a b of Fig. 11. Fig. V represents avertical sectional view of the lower part of a caster in which theball-holder is composed of a single piece and in which the cup D isdispensed with. Fig. VI represents a modification of my invention asapplied to a skate.

Similar letters of reference indicate similar parts.

A indicates what I term the ball-holder, the lower end of which isprovided with a seniispherical-shaped opening, in which is placed theroller-ball B,which bears the weight of the article to which the casteris secured. The ball B is held in place by means of a ring 0, the upperend of which is externally screwthrcaded, the screw-threaded portionbeing fitted to an internally-screw-threaded annular recess in the lowerend of the part A. The ring 0 projects below the center of the ball Band has its lower end contracted, so as to prevent the ball B fromfalling out. The body of the holder A is provided above the ball B witha recess in which is fitted a hardened-steel cup D, the upperor closedend of which has its center portion raised, so as to provide for thereception therein of a ball E, which is preferably of larger diameterthan several balls F,which are held in the cup D and are disposed aroundthe ball E. The balls E and F are of a size such that the ball B willbear on all of them. The holder A is provided with a centralupwardly-extending shank G,

fitted rotatably in a Vertical sleeve H, which is provided near itsupper end with an annular depression I, which enters an annularperipheral recess J in the upper end of the shank G. The depression inthe sleeve cooperating with the said annular recess prevents thedisengagement of the sleeve from the shank, while permitting relativerotation between the parts. At the lower end of the sleeve is providedintegral therewith a horizontal disk K, having suitable verticalopenings therethrough for the insertion of screws, designated by L,designed to secure the caster to the table or chair leg. Between thedisk K and the upper end of the body of the holder Aand around the shankG are located several balls M. Between the balls M and thelower side ofthe disk K is an inverted cup N, provided with a vertical centralopening through which extends the shank Gr. This cup is made of hardenedsteel, preferably. It provides a bearing for the upper sides of theballs M and is preferably secured rigidly to the disk K. In the upperend of the body of the holder A is provided an annular recess, in whichis placed a cup 0, similar to the cup N, but having its open end up.This cup 0 provides a hardened bearing for the under side of the ballsM.

In the modification shown in Fig. V the cups D, N, and O are dispensedwith. Such a construction may be used when the caster is usedcomparatively little-as, forinstance, on pianos or trunks that are notmoved about to any extent. Where, however, the caster is used onarticles that are moved about much, it is better to employ the hardenedcups to prevent wear. In the modification just referred to the ring 0and the body of the holder A are made of a single piece, the

Lower end of the body being swaged inwardly after the balls E, F, and Bhave been placed within the holder.

In Fig. V1 is shown a skate provided with two of the casters constructedin accordance with the principles of my invention. The casters when soused are constructed in the same manner as already described; but theshank G and sleeve H are made much shorter than when the casters are tobe used on chair or table legs.

In the drawings I have shown the skateplatform P provided with twocasters, one under the ball of the foot and one under the heel. Morethan two may be applied, if desired. The caster may be used in aperpendicular position or it may be inclined in any direction withoutinterfering with its operativeness.

In applying my invention the chair-leg is first provided with a verticalhole in its lower end, in which is inserted the sleeve H, after whichthe disk K is secured to the under side of the leg by means of screws L,which are screwed into the wood through the openings provided for themin the disk. The cups D and O are then placed in their appropriateplaces in the holder A, after which the balls E and F are placed in thecup D, the larger ball E occupying the central position. The ball B isthen inserted in the recess in the bottom of the holder, after which thering C is screwed onto the lower end of the holder, thus holding theball B in position. The balls M are then placed in the cup 0, afterwhich the cup N is slipped over the shank G to a position where it restsupon the balls M. The shank G is then inserted into the sleeveopeningand is forced to a position such that the annular depression I of thesleeve will spring into the annular recess J of the shank and preventthe accidental removal of the shank G from the sleeve,while permittingthe rotation of the shank freely within the sleeve. The halls M performa double function. They permit the easy rotation of the shank and holderin the sleeve independently of the rotation of the ball B when thecaster is in the vertical position, and when the caster is inclinedsidewise they furnish a double bearing for the shank and holder andprevent cramping of the shank G in the sleeve due to the side strainupon the shank. In the event of the ball B being made tight in its seatdue to the accumulation of dirt in the recess in which it is placed ordue to the breaking of any of theballs E or F the balls M provide anon-friction bearing for the upper end of-the holder A upon the lowerside of the disk K and permit the rotation with small frictiono of theholder relative to the disk.

My invention may be variously modified to suit the different articles towhich it may be applied without departing from the spirit of myinvention. 6

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-

1. In a caster, the combination with the holder provided with anupwardly-extending 7 shank and a recess in its lower end, of an invertedcup in the said recess, one or more balls located in the said cup, aroller-balllocated in the said recess and bearing upon the said ball orballs in the cup, means for pre- 7 venting the falling out of theroller-ball from the recess, a cup upon the upper end of the holderprovided with an opening through which the shank extends, a series ofballs located in the said cup, an inverted cup upon 8 the said series ofballs, and a sleeve provided with means for securing to the article onwhich the caster is to be used and adapted to receive therein the shank,substantially as described. .8

2. In a caster, the combination with the holder provided with anupwardly-extending shank and a recess in the lower end, of 'a seat inthe said recess, a series of balls 10- 'cated in the said seat, aroller-ball located in 9 the said recess, a ring, the upper end of whichis secured to the lower end of the holder the 7 ring being smaller inits smallest internal diameter than the diameter of the roller ball,

a sleeve provided with adisk at its lower end 9 having an openingadapted to receive the shank, means for detachably securing the shank tothe sleeve while permitting its rotation therein, and a series of ballsupon the holder and grouped around the shank adapt- 1 ed to support thedisk when the shank is inserted into the sleeve, substantially asdescribed.

Signed by me,at Kansas City,Missouri, this 6th day of January, 1898, inpresence oftwo I witnesses.

EDWVARD L. DIMMITT.

Witnesses:

WARREN D. HOUSE, D. W. 0. HOUSE.

